The Pacemaker of the Heart

The Pacemaker of the Heart

The pacemaker of the heart, a tiny area of specialized nervous tissue in the right atrium, sets the heart beating about seventy times a minute. Without it the heart would beat only forty times per minute, which is too slow for the body's needs. The pacemaker, or sinuatrial node, regularly sends out nerve impulses which spread through the two atria, causing them to contract. From the atrioventricular node the contraction spreads down special conducting tissue, the bundle of His, causing the ventricles to contract and pump blood out of the heart.

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[kj9205]

I have an exam today. Thought i'd take a break with this video but the info is incorrect. Withouth the SA node (or pacemaker) the heart will beat at it's unregulated speed which isn't 40 beats per minute.. it's 100 BPM. The Parasympothetic nervous system keeps it running slower for rest, while the sympothetic nervous system increases the HR when exercising or anything else that needs a faster HR.

[willnlizzie]

so many videos from this same user contain incorrect information!!! be warned!!!

[Uniquequal]

I would not use this video as a valid reference for heart physiology as minor details such as the SA node location are stated incorrectly.

[RandomLesson101]

I never thought about the fact having it on the other side would be more efficent. There is a problem, if the blood is pumped futher with one beat, then the pace would have to be slower. If the blood was pumped too hard it could possibly damage alot of organs. This is why it is to simulate a normal heartbeat.

[1091Floyd21]

Now, what you just said, does NOT make sense to me?? I urge you to re-read it.

[RandomLesson101]

Never actually thought about it. but if the blood was pumped further, then the pace would be at a slower rate.

[1091Floyd21]

Wouldn't you think the pacemaker would be on the other side of the heart, so that when the impulse initiated there would be a stronger force to pump the blood further???

[Tahmmo]

One more mistake;

Without the SA node the heart rate would be around 40-60 bpm (due to the AV node) not 40,, AND you will not die with this pace.

You will survive but you wont be very good at most sports.

[Tahmmo]

The video starts wrong, the SA node fires 100 times per minute, it is due to the nerves from the brain that the beat is about 72 pr minute.

If you take the heart out of the body it will fire 100 times/min.

[happilylil]

i am getting good results from Levodyn, i am feeling great and i am having good blood pressure since i started taking it.